In vitro study of potential prebiotic properties of monovarietal extra virgin olive oils

Olive oil, essential ingredient of the Mediterranean diet, is attracting a growing interest due to increasing evidence on its beneficial effects on human health. This study investigated whether extra virgin olive oil (EVOO) possess prebiotic properties. Twenty different monovarietal EVOO samples from 5 Marche region cultivars (Italy) were studied. The prebiotic activity of EVOOs was assessed monitoring the selective stimulation of gut bacterial species and the short chain fatty acids (SCFAs) production, using an in vitro fermentation system. All EVOOs selectively stimulated Lactobacillus spp., with a stronger activity than that observed in the inulin fermentation (positive control). Also, the bifidobacteria population increased; this bifidogenic stimulation was of EVOOs from Raggia cultivar. SCFAs appeared significantly higher after 24 h in all EVOO fermentations than in the control. Acetic and propionic acids production was particularly stimulated. Overall, most of the investigated EVOOs had a potential prebiotic activity, similar or stronger than inulin.

In Vitro Assessment of Postbiotic and Probiotic Commercial Dietary Supplements Recommended for Counteracting Intestinal Dysbiosis in Dogs

Many environmental aspects influence the preservation of a beneficial microbiome in dogs, and gut dysbiosis occurs when imbalances in the intestinal ecosystem cause functional changes in the microbial populations. The authors evaluated the effects of two specific commercial dietary supplements: a combination of a postbiotic and prebiotics (Microbiotal cane®) and a probiotic product (NBF 1®) recommended for counteracting intestinal dysbiosis in dogs, on the gut canine microbiota composition and its metabolic activities (production of short-chain fatty acids). The investigation was performed using an in vitro fermentation system inoculated with dog fecal samples. Microbiotal cane® promoted a more immediate increase in Lactobacillus spp. after the first 6 h of fermentation, whereas NBF 1® promoted the increase at the end of the process only. The two supplements supported an increase in the Bifidobacterium spp. counts only after 24 h. The in vitro abilities of Microbiotal cane® and NBF 1® to increase selectively beneficial bacterial groups producing acetic, propionic, and butyric acids suggest a possible positive effect on the canine gut microbiota, even if further in vivo studies are needed to confirm the beneficial effects on the intestinal health.

SYNBIO® Probiotic and Antioxidant Dietary Supplementation: Clinical Trial Evaluation of Potential Effects on Airline Flight Crew Members’ Well-Being

The irregular lifestyle of airline crew members, wide/adverse job-related exposures, and the impact of temporary hypoxia on gut microbiota well-being have increased concern about the daily recommended dose of certain nutrients among flight crew. The aim of this study was to determine if daily consumption of a SYNBIO® probiotics–elderberry extract supplement (ACTIVE) may contribute to the well-being of flight attendants. Forty healthy crew members enrolled in a double-blind, randomized, placebo-controlled study consumed one ACTIVE capsule/day or placebo for 30 days. Bowel well-being, health-related quality of life, and gastrointestinal tolerance were assessed by validated questionnaires. Saliva and fecal samples were analyzed to determine secretory immunoglobulin-A (sIgA) levels and to characterize gut microbiota composition, respectively. ACTIVE subjects presented a physiological improvement and a statistically significant higher Psychological General Well-Being Index (PGWBI) global score compared to PLACEBO subjects. The ACTIVE subjects showed significantly increased levels of lactobacilli and bifidobacteria compared to the PLACEBO group, while a significant increase in lactobacilli and a significant reduction in Enterobacteriaceae were registered when compared with the beginning of supplementation, confirming the persistence of probiotics in the gastrointestinal tract and the direct antagonism and competitive exclusion effects. Additionally, sIgA levels were significantly higher in the ACTIVE group compared to the baseline and to the PLACEBO group at the end of supplementation. The ACTIVE supplementation might be beneficial to airline crew members, improving their physiological state, their immune defenses, and the strength and efficiency of their gastrointestinal tract when responding to stressful conditions.

Six-Month Synbio® Administration Affects Nutritional and Inflammatory Parameters of Older Adults Included in the PROBIOSENIOR Project

The physiological changes associated with ageing contribute to the incidence of diseases, morbidity, and mortality. For modern society, it is essential to find solutions to improve elderly people's health and quality of life. Among promising strategies, the PROBIOSENIOR project proposed a daily six-month supplementation with new probiotic functional foods and nutraceuticals. The aim of this work was to evaluate the modulating effects of the probiotic diet on inflammatory markers and nutritional status. Ninety-seven elderly volunteers were randomly assigned to either a placebo-diet group or a probiotic-diet group (SYNBIO^®). Faeces, urine, and blood samples were collected before and after the supplementation to determine serum cytokines, biogenic amines, and inflammation markers. Comparing the results obtained before and after the intervention, probiotic supplementations significantly decreased the TNF-α circulating levels and significantly increased those of IGF-1. Biogenic-amine levels showed high variability, with significant variation only for histamine that decreased after the probiotic supplementation. The supplementation influenced the serum concentration of some crucial cytokines (IL-6, IL-8, and MIP-1α) that significantly decreased in the probiotic group. In addition, the Mini Nutritional Assessment questionnaire revealed that the probiotic-supplemented group had a significant improvement in nutritional status. In conclusion, the PROBIOSENIOR project demonstrated how SYNBIO^® supplementation may positively influence some nutritional and inflammatory parameters in the elderly.

Effects of probiotic Lactiplantibacillus plantarum IMC 510 supplementation on metabolic factors in otherwise healthy overweight and obese individuals

AIMS

Probiotic supplementation approach offers the possibility to shape the gut microbiota (GM), enabling the development of innovative formulations able to improve intestinal wellbeing and consequently the related body weight modulation and energy metabolism. In the present clinical study, a new potential probiotic supplement based on Lactiplantibacillus plantarum IMC 510 was studied for weight management.

METHODS AND RESULTS

Quantitative characterization by qPCR of representative bacterial groups of GM was used to determine the microbiota modulation at different supplementation periods. Furthermore, measurement of the endpoints linked to weight control (Body Mass Index (BMI), body weight, waist circumference) was assessed. Specific questionnaires to evaluate the impact on psychological and physiological point of view were performed. Results showed that after 90 days - Lact. plantarum IMC 510 supplementation brought an improvement of endpoints linked to weight control and healthy status, although no significant changes in the microbiota composition were reported for analysed bacterial groups, except for Lactobacillus spp. and Bifidobacterium spp.

CONCLUSIONS

We concluded that Lact. plantarum IMC 510 supplementation could be an interesting tool for weight management. More studies are needed to understand the impact on GM, for example evaluating the production of short chain fatty acids (SCFA), since their important role in dietary metabolism. Further research is necessary to better elucidate the relationship between GM and overweight and the mechanism of action by which Lact. plantarum IMC 510 modifies body weight.

SIGNIFICANCE AND IMPACT OF THE STUDY

However, these promising outcomes represent a clear advantage of probiotic supplementation and identify a new potential probiotic as a novel and safe therapeutic approach in the obesity prevention and management.

Supplementation with Lactiplantibacillus plantarum IMC 510 Modifies Microbiota Composition and Prevents Body Weight Gain Induced by Cafeteria Diet in Rats

Changes in functionality and composition of gut microbiota (GM) have been associated and may contribute to the development and maintenance of obesity and related diseases. The aim of our study was to investigate for the first time the impact of Lactiplantibacillus (L.) plantarum IMC 510 in a rat model of diet-induced obesity, specifically in the cafeteria (CAF) diet. This diet provides a strong motivation to voluntary overeat, due to the palatability and variety of selected energy-dense foods. The oral administration for 84 days of this probiotic strain, added to the CAF diet, decreased food intake and body weight gain. Accordingly, it ameliorated body mass index, liver and white adipose tissue weight, hepatic lipid accumulation, adipocyte size, serum parameters, including glycemia and low-density lipoprotein levels, in CAF fed rats, potentially through leptin control. In this scenario, L. plantarum IMC 510 showed also beneficial effects on GM, limiting the microbial imbalance established by long exposure to CAF diet and preserving the proportion of different bacterial taxa. Further research is necessary to better elucidate the relationship between GM and overweight and then the mechanism of action by which L. plantarum IMC 510 modifies weight. However, these promising results prompt a clear advantage of probiotic supplementation and identify a new potential probiotic as a novel and safe therapeutic approach in obesity prevention and management.

Comprehensive pan-genome analysis of Lactiplantibacillus plantarum complete genomes

Aims

The aim of this work was to refine the taxonomy and the functional characterization of publicly available Lactiplantibacillus plantarum complete genomes through a pan‐genome analysis. Particular attention was paid in depicting the probiotic potential of each strain.

Methods and results

Complete genome sequence of 127 L. plantarum strains, without detected anomalies, was downloaded from NCBI. Roary analysis of L. plantarum pan‐genome identified 1436 core, 414 soft core, 1858 shell and 13,203 cloud genes, highlighting the ‘open’ nature of L. plantarum pan‐genome. Identification and characterization of plasmid content, mobile genetic elements, adaptative immune system and probiotic marker genes (PMGs) revealed unique features across all the L. plantarum strains included in the present study. Considering our updated list of PMGs, we determined that approximatively 70% of the PMGs belongs to the core/soft‐core genome.

Conclusions

The comparative genomic analysis conducted in this study provide new insights into the genomic content and variability of L. plantarum.

Significance and Impact of the Study

This study provides a comprehensive pan‐genome analysis of L. plantarum, including the largest number (N = 127) of complete L. plantarum genomes retrieved from publicly available repositories. Our effort aimed to determine a solid reference panel for the future characterization of newly sequenced L. plantarum strains useful as probiotic supplements.

Chemical and organoleptic changes of curd cheese stored in new and reused active packaging systems made of Ag-graphene-TiO2-PLA

The study reports obtaining, characterization and evaluation of the preservation efficacy of nano-Ag-graphene-TiO₂-polylactic acid (PLA) film during the storage of the curd cheese. The reusability of the active package was also evaluated. The mechanical resistance of the film was improved by 30% following the composite addition. Water vapour permeability decreased by 11-27% when the composite was incorporated into PLA in a mass percentage ranged between 0.5 and 3%. The highest fat permeability was obtained for PLA3% at 4 °C. The oxygen permeability of PLA3% is 24.6% lower than that of neat-PLA. PLA0.5% and PLA3% presented the highest antibacterial activity. PLA3% achieved the lowest solubility in food simulants at 4 °C compared to PLA and reference. The best active packages for curd storage were PLA0.5% and PLA3%. They showed also the lowest depreciation from the first to the second use. Their active role is kept 100% and 85% respectively, during the second use.

Modifying the Silver-Titania Nanocomposites with Carbonaceous Materials to Remove the Pollutants from Domestic Waste Water

The aim of this study was to prepare and characterize nanostructured composites based of TiO₂, carbonaceus materials (GN or GO) and Ag and the test their capacity to remove the pollutants from domestic wastewater. The composites were characterized by IR and UV-Vis spectroscopy, X-ray diffraction, electron microscopy and nitrogen adsorption-desorption measurements. The photocatalytic activity was measured from the experiment of salicylic acid (SA) degradation. The capacity to remove the pollutants from domestic wastewater was performed by considering the absorbance of residual solution at 200 nm. The non-calcined composites have high specific surface area (˜300 m²/g), but nitrogen adsorption-desorption isotherms showed a porous structure with closed pores. The porosity of the thermal treated composites is about 10 times less, but the pores are open. The salicylic acid was 94% degraded over all composites, showing their efficient photoactivity. A percent of 70% of pollutants were removed over the calcined composites with GN and ˜67% on those with GO. It was no statistically significant difference between the photocatalytical efficiency of GN- and GO-based composites. Even if the calcined composites have the specific surface area about 10 times lower, their lower gap energy, higher degree of crystallinity and photocatalytic activity make them efficient candidates for removal of pollutants from domestic waste water. The photodegradation mechanism occurred mostly by π-π interactions between GN/GO and pollutant molecules.

Proteomic characterization of kefir milk by two-dimensional electrophoresis followed by mass spectrometry

Kefir is a type of fermented milk obtained thanks to the introduction of "kefir grains" in mammalian milk. Kefir grains consist of lactic and acetic acid bacteria and yeasts in alternative proportions that are held together by a matrix of complex sugars known as "kefiran." Thanks to the fermentative process, the kefir milk is rich in nutraceutical substances such as amino acids, vitamins, and mineral salts. The most valuable compounds of kefir fermentation are mainly lactic acid, exopolysaccharides, and bioactive peptides, the resulting products of proteolytic release from milk proteins (caseins and whey proteins). Among the nutraceutical properties of kefir are antimicrobial and antitumor activity, immunomodulating effect, and cholesterol-lowering effect. Therefore, in light of these intriguing properties of kefir milk, in this work, a proteomic analysis, by two-dimensional electrophoresis followed by mass spectrometry, has been performed. As a result, milk-derived polypeptides were identified in commercial kefir milk from organic farming. In particular, polypeptides deriving from κ-, α_s1 -, and α_s2 -caseins that may have potentially beneficial effects on human health have been detected.

Clinical Features and Disease Management in Adult Patients With Atopic Dermatitis Receiving Care at Reference Hospitals in Brazil: the ADAPT Study

BACKGROUND

Atopic dermatitis is a chronic inflammatory skin disease with a prevalence of 0.02% to 8.1% in adults. Adult patients with moderate-to-severe atopic dermatitis are affected by frequent relapses and a significant disease burden. Objective: To determine the clinical, immunological, and therapeutic profile of Brazilian adults with atopic dermatitis.

METHODS

A multicenter, observational, retrospective, descriptive registry-based study was conducted at reference hospitals between December 2016 and October 2017. The data collected were demographics, personal and family history of atopic diseases, clinical manifestations, laboratory tests, disease severity and management.

RESULTS

Of the 187 patients included in the analysis, 56.1% were female and 71.7% were White, with a mean age of 24.7 years. Mean follow-up was 9 years. Asthma or other allergic diseases were reported by 80.2% of patients. The main comorbidity was hypertension (10.2%), and common disease manifestations included pruritus and erythema. Lesions generally affected flexural and nonflexural areas, with typical morphology. Around 83% of patients had moderate-to-severe disease, and 8.6% reported at least 1 hospitalization. Most patients received topical and/or systemic pharmacological therapies, including omalizumab (5.9%); 4.3% received phototherapy. Moreover, 66.8% of patients received adjuvant therapy, and 79.1% changed or discontinued treatment for atopic dermatitis due to remission (46.5%), poor effectiveness (33.7%), or lack of adherence (12.9%). Most patients presented characteristics of type 2 inflammation, with immunoglobulin E levels above 100 IU/mL (94.4%) and peripheral blood eosinophils above 5% (55.9%).

CONCLUSION

Brazilian adult patients with severe atopic dermatitis need treatment to efficiently control the disease and improve quality of life.

Development and validation of a GC-FID method for the analysis of short chain fatty acids in rat and human faeces and in fermentation fluids

Short-chain fatty acids (SCFAs) are gut microbiota metabolites recognized for their beneficial effects on the host organism. In this study, a simple and rapid sample preparation method combined to SCFAs analysis by direct injection and gas chromatography coupled with flame ionization detection (GC-FID), for the determination and quantification of eight SCFAs (acetic, propionic, i-butyric, butyric, i-valeric, valeric, i-caproic and caproic acids) in rat, mice and human faeces and in fermentation fluids samples, has been developed and validated. The method consists of extraction of the SCFAs by ethyl ether after acidification of the samples. The effect of the number of extractions has been assessed in order to optimize the procedure and to obtain a satisfactory yield for all the analyzed SCFAs. The increase of the extracted analytes quantity was significant passing from 1 to 2 and from 2 to 3 extractions (P < 0.05), while no significant differences were found performing 3, 4 or 5 extractions (P > 0.05). The SCFAs extracted are directly analyzed by GC-FID without derivatization and separated on a polyethylene glycol nitroterephthalic acid modified coated capillary column, with a chromatographic run time of 13 min. The proposed method showed good sensitivity, with limits of quantifications in the range 0.14-0.48 µM for SCFAs from propionic to caproic acids and 2.12 µM for acetic acid; recovery was between 80.8 and 108.8% and intraday and interday repeatability in the range 0.6-5.0% of precision (RSD, %) The optimized method is suitable for the quantitative analysis of SCFAs in real samples of rat, mouse and human faeces and in fermentation fluids, and it can be applied also to very small amount of faecal sample (20 mg).

Antimicrobial activity of SYNBIO® probiotic formulation in pathogens isolated from chronic ulcerative lesions: in vitro studies

AIMS

Probiotics have the ability to enhance the immune system, produce anti-inflammatory action and promote wound healing process. The first aim of the study was to isolate pathogenic micro-organisms from sites of chronic ulcerative lesion. The second aim was to evaluate probiotic efficacy of SYNBIO^® (1:1 combination of Lactobacillus rhamnosus IMC 501^® and Lactobacillus paracasei IMC 502^® ) in counteracting wound infections.

METHODS AND RESULTS

Several bacterial pathogens were isolated from chronic ulcerative lesions and identified by morphological, biochemical and molecular techniques. SYNBIO^® probiotic formulation was investigated for its antimicrobial activity, minimum inhibitory concentration, co-aggregation and adherence capacity against the isolated pathogens. Moreover, SYNBIO was also tested in combination with some medical devices, using an in vitro model, in order to simulate a real ulcerative wound infection. Probiotic formulation demonstrated an inhibitory action against all the tested pathogens and their mixture (MIX), with an increased ability of co-aggregation during time. In addition, the adhesion percentage of probiotic micro-organisms to human keratinocyte (HaCaT cells) and human fibroblasts (NHF), calculated by an in vitro model, was 19% and 17% respectively, highlighting the possibility to create a protective environment preventing pathogens' biofilm formation in order to contrast infections.

CONCLUSIONS

SYNBIO^® probiotics showed a very good antimicrobial capacity and adhesion percentage to HaCaT cells and fibroblasts, giving the opportunity to be successfully used as complement to conventional therapies in the treatment of chronic ulcerative lesions.

SIGNIFICANCE AND IMPACT OF THE STUDY

A new therapeutic approach with probiotics (supplemented in topical applications, excluding side effects) able to eliminate pathogenic micro-organisms and improve healing of chronic ulcerative lesions.

Effects of Lactogen 13, a New Probiotic Preparation, on Gut Microbiota and Endocrine Signals Controlling Growth and Appetite of Oreochromis niloticus Juveniles

In the present study, Nile tilapia Oreochromis niloticus was used as experimental model to study the molecular effects of a new probiotic preparation, Lactogen 13 (Lactobacillus rhamnosus IMC 501® encapsulated with vegetable fat matrices by spray chilling and further indicated as probiotic microgranules), on growth and appetite during larval development. Probiotic microgranules were administered for 30 days to tilapia larvae starting from first feeding. Molecular analysis using high-throughput sequencing revealed that the probiotic could populate the gastrointestinal tract and modulate the microbial communities by significantly increasing the proportion of Lactobacillus as well as reducing the proportion of potential pathogens such as members of the Family Microbacteriaceae, Legionellaceae, and Weeksellaceae. Morphometric analysis evidenced that body weight and total length significantly increased after probiotic treatment. This increase coincided with the modulation of genes belonging to the insulin-like growth factors (igfs) system and genes involved on myogenesis, such as myogenin, and myogenic differentiation (myod). Alongside the improvement of growth, an increase of feed intake was evidenced at 40 days post-fertilization (dpf) in treated larvae. Gene codifying for signals belonging to the most prominent systems involved in appetite regulation, such as neuropeptide y (npy), agouti-related protein (agrp), leptin, and ghrelin were significantly modulated. These results support the hypothesis that gastrointestinal (GI) microbiota changes due to probiotic administration modulate growth and appetite control, activating the endocrine system of tilapia larvae.

Correction to: Effects of Lactogen 13, a New Probiotic Preparation, on Gut Microbiota and Endocrine Signals Controlling Growth and Appetite of Oreochromis niloticus Juveniles

The original version of this article unfortunately contained mistakes in Authors First name/Family name order. Please refer to this paper as Gioacchini et al. and not as Giorgia et al.

Abusive use of antibiotics in poultry farming in Cameroon and the public health implications

The types and methods of use of antibiotics in poultry farms in Cameroon, residual levels and potential microbial resistance were determined. A questionnaire-based survey identified the different antibiotics used and high-performance liquid chromatography (HPLC) was used to determine residual levels of antibiotics. Pathogens were isolated, identified by use of commercial API kits and minimum inhibition concentration (MIC) was determined. Oxytetracyclin, tylocip and TCN (oxytetracycline, chloramphenicol and neomycin) were the most frequently used antibiotics. Antibiotics screened by HPLC were chloramphenicol, tetracycline and vancomycin. All of them except vancomycin were detected, and the concentration of these antibiotics was higher than the maximum residual limits (MRL) set by regulatory authorities. No residues of various antibiotics were found in egg albumen or yolk. The concentration of tetracycline was significantly higher in liver (150 ± 30 µg/g) than in other tissues. Foodborne pathogens, including Salmonella spp., Staphylococcus spp., Listeria spp., Clostridium spp. and Escherichia spp., were identified. Most of the pathogens were resistant to these various antibiotics tested. These findings imply the need for better management of antibiotic use to control sources of food contamination and reduce health risks associated with the presence of residues and the development of resistant pathogens by further legislation and enforcement of regulations on food hygiene and use of antibiotics.

Impact of Probiotic SYNBIO(®) Administered by Vaginal Suppositories in Promoting Vaginal Health of Apparently Healthy Women

The purpose of this study was to investigate whether vaginal administration of probiotic Lactobacillus results in their colonization and persistence in the vagina and whether it promotes normalization and maintenance of pH and Nugent score. A single-arm, open-label controlled towards the baseline (pre-post) study including 35 apparently healthy women was conducted. Each woman was examined three times during the study. Women were instructed to receive daily for 7 days, the probiotic suppositories SYNBIO(®) gin (Lactobacillus rhamnosus IMC 501(®) and Lactobacillus paracasei IMC 502(®)). Vaginal swabs were collected during visit 1, 2, and 3 to determine the total lactobacilli count, the presence of the two administered bacteria, the measure of the pH, and the estimation of Nugent score. Evaluation of treatment tolerability was based on analysis of the type and occurrence of adverse events. The probiotic vaginal suppository was well tolerated and no side effects were reported. Intermediate Nugent score was registered in 40 % of women at visit 1 and these intermediate scores reverted to normal at day 7 (end of treatment) in 20 % of subjects. Administration of SYNBIO(®) gin contributed to a significant increase in the lactobacilli level at visit 2. Molecular typing revealed the presence of the two strains originating from SYNBIO(®) gin in 100 % of women at visit 2 and 34 % at visit 3. No significant changes were registered for pH between visits. The SYNBIO(®) gin product is safe for daily use in healthy women and it could be useful to restore and maintain a normal vaginal microbiota.

Changes on fecal microbiota in rats exposed to permethrin during postnatal development

Alteration of the gut microbiota through diet and environmental contaminants may disturb the mammalian digestive system, leading to various diseases. Because most exposure to environmentally pyrethroid pesticides such as permethrin (PERM) occurs through the diet, the commensal gut microbiota is likely to be exposed to PERM. The study aimed at evaluating the effect of low-dose exposure to PERM in early life on the composition of fecal microbiota in rats. Over a 4-month follow-up period, fecal microbiota and short-chain fatty acids were measured in order to identify possible differences between PERM-treated rats and controls. Further in vitro antimicrobial experiments were conducted to establish the antibacterial activity of PERM against different strains to obtain Minimal Inhibitory Concentrations. The main finding focused on the reduced abundance of Bacteroides-Prevotella-Porphyromonas species, increased Enterobacteriaceae and Lactobacillus in PERM-treated rats compared to controls. Changes of acetic and propionic acid levels were registered in PERM-treated group. From in vitro studies, PERM showed higher antibacterial activity against beneficial bacteria such as Bifidobacterium and Lactobacillus paracasei, while to inhibit potential pathogens as Staphylococcus aureus and Escherichia coli PERM concentration needed to be increased. In summary, exposure to PERM could affect the fecal microbiota and could be a crucial factor contributing to the development of diseases.

In vitro evaluation on HeLa cells of protective mechanisms of probiotic lactobacilli against Candida clinical isolates

AIMS

To characterize in vitro the ability of human Lactobacillus strains to inhibit the adhesion, to displace and to compete with clinically isolated Candida strains.

METHODS AND RESULTS

Three types of assays were performed to determine the inhibitory effect of Lactobacillus plantarum 319, Lactobacillus rhamnosus IMC 501, Lactobacillus paracasei IMC 502 and a specific probiotic combination (SYNBIO) on adhesion of Candida pathogens to HeLa cells: blockage by exclusion (lactobacilli and HeLa followed by pathogens), competition (lactobacilli, HeLa and pathogens together) and displacement (pathogens and HeLa followed by the addition of lactobacilli). Bacterial adhesion to HeLa was quantified by microscopy after May-Grünwald/Giemsa stain. The inhibition results highlight a significant (P < 0·05) competition of the considered probiotics against all the Candida strains. The results suggest that the probiotic strains used in this study could prevent colonization of the urogenital tract by relevant pathogens such as Candida strains through barrier and interference mechanisms (mainly displacement and competition), but the degree of inhibition of adhesion was bacterial strain-dependent.

CONCLUSIONS

The results support the potential of these Lactobacillus probiotic strains as anti-infective agents in the vagina and encourage further studies about their capacity to prevent and manage urogenital tract infections in females.

SIGNIFICANCE AND IMPACT OF THE STUDY

To optimize the defensive properties of the vaginal microbiota, improving the health of many women by probiotic intervention.

In vitro evaluation of antimicrobial activity of Lactobacillus rhamnosus IMC 501(®) , Lactobacillus paracasei IMC 502(®) and SYNBIO(®) against pathogens

AIMS

Probiotic lactobacilli have a great potential to produce antimicrobial compounds that inhibit and control the microbial pathogen growth. The antimicrobial and antifungal activities of two probiotic strains, Lactobacillus rhamnosus IMC 501(®) and Lactobacillus paracasei IMC 502(®) , and their 1 : 1 combination, named SYNBIO(®) , were studied using four different methods.

METHODS AND RESULTS

Using two modified streak methods and a well diffusion method, the inhibitory activity of the probiotics and their metabolites towards six Gram-positive, nine Gram-negative pathogenic bacterial strains and eight Candida strains was tested. Antagonistic effect of probiotic Lactobacillus strains was also investigated by coculturing assay highlighting a significant inhibition of most of the pathogens tested in this study. The combination SYNBIO(®) showed a microbicidal activity against most of the strains tested in the study.

CONCLUSIONS

Compared with the control, most of the pathogenic bacteria and yeast were inhibited by all probiotic strains tested to various degrees.

SIGNIFICANCE AND IMPACT OF THE STUDY

Screening Lactobacillus strains according to their activity in various environmental conditions could precede the clinical efficacy studies for adjunct treatment with probiotics in cure of different gastrointestinal and vaginal tract infections.

Effect of buckwheat flour and oat bran on growth and cell viability of the probiotic strains Lactobacillus rhamnosus IMC 501®, Lactobacillus paracasei IMC 502® and their combination SYNBIO®, in synbiotic fermented milk

Fermented foods have a great significance since they provide and preserve large quantities of nutritious foods in a wide diversity of flavors, aromas and texture, which enrich the human diet. Originally fermented milks were developed as a means of preserving nutrients and are the most representatives of the category. The first aim of this study was to screen the effect of buckwheat flour and oat bran as prebiotics on the production of probiotic fiber-enriched fermented milks, by investigating the kinetics of acidification of buckwheat flour- and oat bran-supplemented milk fermented by Lactobacillus rhamnosus IMC 501®, Lactobacillus paracasei IMC 502® and their 1:1 combination named SYNBIO®. The probiotic strains viability, pH and sensory characteristics of the fermented fiber-enriched milk products, stored at 4 °C for 28 days were also monitored. The results showed that supplementation of whole milk with the tested probiotic strains and the two vegetable substrates results in a significant faster lowering of the pH. Also, the stability of L. rhamnosus IMC 501®, L. paracasei IMC 502® and SYNBIO® during storage at 4 °C for 28 days in buckwheat flour- and oat bran-supplemented samples was remarkably enhanced. The second aim of the study was to develop a new synbiotic product using the best combination of probiotics and prebiotics by promoting better growth and survival and be acceptable to the consumers with high concentration of probiotic strain. This new product was used to conduct a human feeding trial to validate the fermented milk as a carrier for transporting bacterial cells into the human gastrointestinal tract. The probiotic strains were recovered from fecal samples in 40 out of 40 volunteers fed for 4 weeks one portion per day of synbiotic fermented milk carrying about 10(9) viable cells.

Lactobacillus rhamnosus accelerates zebrafish backbone calcification and gonadal differentiation through effects on the GnRH and IGF systems

Endogenous microbiota play essential roles in the host’s immune system, physiology, reproduction and nutrient metabolism. We hypothesized that a continuous administration of an exogenous probiotic might also influence the host’s development. Thus, we treated zebrafish from birth to sexual maturation (2-months treatment) with Lactobacillus rhamnosus, a probiotic species intended for human use. We monitored for the presence of L. rhamnosus during the entire treatment. Zebrafish at 6 days post fertilization (dpf) exhibited elevated gene expression levels for Insulin-like growth factors -I and -II, Peroxisome proliferator activated receptors -α and -β, VDR-α and RAR-γ when compared to untreated-10 days old zebrafish. Using a gonadotropin-releasing hormone 3 GFP transgenic zebrafish (GnRH3-GFP), higher GnRH3 expression was found at 6, 8 and 10 dpf upon L. rhamnosus treatment. The same larvae exhibited earlier backbone calcification and gonad maturation. Noteworthy in the gonad development was the presence of first testes differentiation at 3 weeks post fertilization in the treated zebrafish population -which normally occurs at 8 weeks- and a dramatic sex ratio modulation (93% females, 7% males in control vs. 55% females, 45% males in the treated group). We infer that administration of L. rhamnosus stimulated the IGF system, leading to a faster backbone calcification. Moreover we hypothesize a role for administration of L. rhamnosus on GnRH3 modulation during early larval development, which in turn affects gonadal development and sex differentiation. These findings suggest a significant role of the microbiota composition on the host organism development profile and open new perspectives in the study of probiotics usage and application.

Influence of a combination of two potential probiotic strains, Lactobacillus rhamnosus IMC 501® and Lactobacillus paracasei IMC 502® on bowel habits of healthy adults

AIMS

This study aims to investigate the effect of different kinds of food products enriched with a combination of two potential probiotic strains, Lactobacillus rhamnosus IMC 501(®) and Lactobacillus paracasei IMC 502(®), on bowel habits of healthy adults.

METHODS AND RESULTS

Fifty healthy volunteers took part in a double-blind placebo probiotic feeding study (25 fed probiotics, 25 fed placebo) for 12 weeks. Each volunteer ingested daily one or more food products enriched with a combination of the two potential probiotic strains (probiotic group) or the same food products without the probiotics (control group). Faecal samples were collected before, at the end and 2 weeks later the intervention period, and some of the main groups of faecal bacteria were enumerated by plate count and real-time PCR. Questionnaires on bowel habits were submitted to volunteers. After the intervention, a significant increase in faecal lactobacilli and bifidobacteria were observed in the probiotic group, and stool frequency and stool volume were higher in the probiotic group than in the placebo group.

CONCLUSIONS

Daily consumption of food products enriched with the two potential probiotic strains, Lact. rhamnosus IMC 501(®) and Lact. paracasei IMC 502(®) , contributes to improve intestinal microbiota with beneficial properties and enhances bowel habits of healthy adults.

SIGNIFICANCE AND IMPACT OF THE STUDY

The study revealed that Lact. rhamnosus IMC 501(®) and Lact. paracasei IMC 502(®) exert a positive effect, in terms of improved bowel habits, on healthy adults.

Pilot-scale production and viability analysis of freeze-dried probiotic bacteria using different protective agents

The functional food industry requires an improvement of probiotic strain stability during storage, especially when they are stored at room temperature. In this study, the viability of freeze-dried Lactobacillus rhamnosus IMC 501(®) and Lactobacillus paracasei IMC 502(®) using different protective agents (i.e., glycerine, mannitol, sorbitol, inulin, dextrin, Crystalean(®)) was determined and compared with semi skimmed milk (SSM) control. No significant differences were observed between the tested protectants and the control (SSM) during storage at refrigerated conditions. During storage at room temperature, only glycerine was found to stabilize viability better than other tested substances.

Effect of dietary probiotics on clownfish: a molecular approach to define how lactic acid bacteria modulate development in a marine fish

We set out to determine whether probiotic addition would improve larval development in the false percula clownfish Amphiprion ocellaris and to determine what molecular responses could be observed in the larvae following probiotic exposure. We supplied the probiotic bacterial strain Lactobacillus rhamnosus IMC 501 to clownfish larvae from the first day posthatch simultaneously by live prey and with addition to rearing water (group 2) and exclusively by live prey (group 3). We observed twofold higher body weight in both clownfish larvae and juveniles when probiotics were supplied via live prey and added to the rearing water. In addition, development was accelerated with metamorphosis occurring 3 days earlier in fingerlings treated with probiotic. Alteration in molecular biomarkers supported the faster growth observation. There was significantly increased gene expression of factors involved in growth and development (insulin-like growth factors I and II, myostatin, peroxisome proliferator-activated receptors alpha and beta, vitamin D receptor alpha, and retinoic acid receptor gamma) when probiotics were delivered via live prey and added to the rearing water. Moreover, probiotic treatment lessened the severity of the general stress response as exhibited by lower levels of glucocorticoid receptor and 70-kDa heat shock protein gene expression. Furthermore, an improvement of skeletal head development was observed, with a 10-20% reduction in deformities for juveniles treated with probiotic. All data suggest a potent effect on development resulting from the administration of lactic acid bacteria to larval clownfish, and this study provides a preliminary molecular entry path into the investigation of mechanisms responsible for probiotic enhancement in fish development.

Probiotic properties of Lactobacillus rhamnosus and Lactobacillus paracasei isolated from human faeces

BACKGROUND

The possibility of using microbes to maintain health, and to prevent or treat disease is a topic as old as microbiology. The research of novel probiotic strains is important in order to satisfy the increasing request of the market and to obtain functional products in which the probiotic cultures are more active and with better probiotic characteristics than those already present on the market.

AIM OF THE STUDY

In this study, the probiotic potential of Lactobacillus strains isolated from Italian elderly human faeces was investigated.

METHODS

The Lactobacillus strains were identified and examined for resistance to gastric acidity and bile toxicity, adhesion to HT-29 cells, antimicrobial activities, antibiotic susceptibility and plasmid profile. Survival of the strains through human intestine was examined in a 3 months human feeding trial.

RESULTS

Two strains, Lactobacillus rhamnosus IMC 501 and Lactobacillus paracasei IMC 502, tolerated well low pH and bile acids. In antimicrobial activity assays, both strains showed inhibitory properties towards selected potential harmful microorganisms, particularly against Candida albicans. The two selected strains expressed high in vitro adherence to HT-29 cells increasing this characteristic when they are used in combination and they were resistant to vamcomycin, colistin sulphate, gentamicin, oxolinic acid and kanamycin. Moreover, the two strains could be recovered from stools of volunteers after the feeding trials.

CONCLUSIONS

Lactobacillus rhamnosus IMC 501 and L. paracasei IMC 502 present favourable strain-specific properties for their utilisation as probiotics in functional foods and the high adhesion ability of the L. rhamnosus IMC 501 and L. paracasei IMC 502 used in combination, confirmed by both in vitro and in vivo study, indicate that the two bacterial strains could be used as health-promoting bacteria.

Effects of different digestible carbohydrates on bile acid metabolism and SCFA production by human gut micro-flora grown in an in vitro semi-continuous culture

The main source of carbon in the human large intestine comes from carbohydrates like starches and oligosaccharides which remain unchanged by gastric digestion. These polysaccharides are metabolised in the colon by saccharolytic bacteria whose composition is dependent upon the substrate availability. Among the metabolites produced, the short-chain fatty acids (SCFA) are important for colon function and to prevent diseases. In particular, butyrate affects several cellular functions (proliferation, membrane synthesis, sodium absorption), and it has been shown to be protective against colorectal cancer. In addition, faecal bacteria are responsible for the conversion of primary bile acids (BA) to secondary BA, which are considered tumor promoters. In this study we investigated the in vitro effect of different substrates (CrystaLean starch, xylo-oligosaccharides, corn starch) supplied to human faecal micro-flora, on the SCFA production, on the bowel micro-flora composition and on the primary BA conversion rate. In addition, with corn starch as substrate, we considered the effect of enriching normal human faecal micro-flora with lactobacilli and bifidobacteria, on the above reported parameters.

Differences in fecal microbiota in different European study populations in relation to age, gender, and country: a cross-sectional study

A cross-sectional study on intestinal microbiota composition was performed on 230 healthy subjects at four European locations in France, Germany, Italy, and Sweden. The study participants were assigned to two age groups: 20 to 50 years (mean age, 35 years; n = 85) and >60 years (mean age, 75 years; n = 145). A set of 14 group- and species-specific 16S rRNA-targeted oligonucleotide probes was applied to the analysis of fecal samples by fluorescence in situ hybridization coupled with flow cytometry. Marked country-age interactions were observed for the German and Italian study groups. These interactions were inverse for the predominant bacterial groups Eubacterium rectale-Clostridium coccoides and Bacteroides-Prevotella. Differences between European populations were observed for the Bifidobacterium group only. Proportions of bifidobacteria were two- to threefold higher in the Italian study population than in any other study group, and this effect was independent of age. Higher proportions of enterobacteria were found in all elderly volunteers independent of the location. Gender effects were observed for the Bacteroides-Prevotella group, with higher levels in males than in females. In summary, age-related differences in the microbiota makeup were detected but differed between the study populations from the four countries, each showing a characteristic colonization pattern.

Red wine polyphenols influence carcinogenesis, intestinal microflora, oxidative damage and gene expression profiles of colonic mucosa in F344 rats

Polyphenols from tea and other beverages such as red wine have been regarded with interest as possible chemopreventive agents against cancer. Here we report that red wine polyphenols (50 mg/kg) administered with the diet to F344 rats for 16 weeks inhibited colon carcinogenesis induced by azoxymethane (AOM, 7.4 mg/kg, total dose 74 mg/kg) or dimethylhydrazine (DMH, 30 mg/kg, total dose, 300 mg/kg). Polyphenol-treated animals had a consistently lower tumour yield compared to controls. In polyphenol-treated rats, the main bacterial strains in the faeces at sacrifice were Bacteroides, Lactobacillus and Bifidobacterium spp., whereas microorganisms predominantly identified in control-fed rats were Bacteroides, Clostridium and Propionibacterium spp. Wine polyphenols (57 mg/kg for 10 days, by gavage), administered to rats not treated with carcinogens, produced a significant decrease in the basal level of DNA oxidative damage of the colon mucosa as measured with the comet assay (average pyrimidine oxidation was reduced by 62% and purine oxidation by 57%, p<0.05). To further explore the molecular effects of wine polyphenols we used the microarray technology to study gene expression profiles: rats were treated with 50 mg/kg wine polyphenols for 14 days, mixed in the diet. Global expression analysis of 5707 genes revealed an extensive down-regulation of genes involved in a wide range of physiological functions, such as metabolism, transport, signal transduction and intercellular signalling. By analysing metabolic pathways with the GenMAPP software program we observed that two major regulatory pathways were down-regulated in the colon mucosa of polyphenols-treated rats: inflammatory response and steroid metabolism. We also found a down-regulation of many genes regulating cell surface antigens, metabolic enzymes and cellular response to oxidative stress. In conclusion, reduction of oxidative damage, modulation of colonic flora and variation in gene expression may all concur in the modulation of intestinal function and carcinogenesis by wine polyphenols.

Effects of fermentation products of pro- and prebiotics on trans-epithelial electrical resistance in an in vitro model of the colon

Evidence from in vivo and in vitro studies suggests that the consumption of pro- and prebiotics may inhibit colon carcinogenesis; however, the mechanisms involved have, thus far, proved elusive. There are some indications from animal studies that the effects are being exerted during the promotion stage of carcinogenesis. One feature of the promotion stage of colorectal cancer is the disruption of tight junctions, leading to a loss of integrity across the intestinal barrier. We have used the Caco-2 human adenocarcinoma cell line as a model for the intestinal epithelia. Trans-epithelial electrical resistance measurements indicate Caco-2 monolayer integrity, and we recorded changes to this integrity following exposure to the fermentation products of selected probiotics and prebiotics, in the form of nondigestible oligosaccharides (NDOs). Our results indicate that NDOs themselves exert varying, but generally minor, effects upon the strength of the tight junctions, whereas the fermentation products of probiotics and NDOs tend to raise tight junction integrity above that of the controls. This effect was bacterial species and oligosaccharide specific. Bifidobacterium Bb 12 was particularly effective, as were the fermentation products of Raftiline and Raftilose. We further investigated the ability of Raftilose fermentations to protect against the negative effects of deoxycholic acid (DCA) upon tight junction integrity. We found protection to be species dependent and dependent upon the presence of the fermentation products in the media at the same time as or after exposure to the DCA. Results suggest that the Raftilose fermentation products may prevent disruption of the intestinal epithelial barrier function during damage by tumor promoters.

Resistant starch modifies gut microflora and microbial metabolism in human flora-associated rats inoculated with faeces from Italian and UK donors

The effect of sucrose and resistant starch ('CrystaLean'--a retrograded, amylose starch) on human gut microflora and associated parameters was studied in human flora-associated (HFA) rats, colonized with microfloras from UK or Italian subjects, to determine whether such floras were affected differently by dietary carbohydrates. Consumption of the resistant starch diet resulted in significant changes in four of the seven main groups of bacteria enumerated. In both the UK and Italian flora-associated rats, numbers of lactobacilli and bifidobacteria were increased 10-100-fold, and there was a concomitant decrease in enterobacteria when compared with sucrose-fed rats. The induced changes in caecal microflora of both HFA rat groups were reflected in changes in bacterial enzyme activities and caecal ammonia concentration. Although it had little effect on caecal short-chain fatty acid concentration, CrystaLean markedly increased the proportion of n-butyric acid in both rat groups and was associated with a significant increase in cell proliferation in the proximal colon of the Italian flora-associated rats. CrystaLean appeared to play a protective role in the colon environment, lowering caecal ammonia concentration, caecal pH and beta-glucuronidase activity.

The effect of sucrose or starch-based diet on short-chain fatty acids and faecal microflora in rats

An investigation was carried out to determine whether variations of dietary carbohydrates could modify the colonic flora in rats. Sprague-Dawley rats were fed with two equicaloric diets based on the AIN-76 diet (American Institute of Nutrition 1977) but differing from that diet in content of carbohydrates, i.e. high sucrose (64%) of high corn starch (64%). Feeding was continued for 9 months ad libitum and no variation in weight gain was recorded among the different diets. A prevalence of aerobes, and a significant reduction in the ratio anaerobes/aerobes in the faeces of rats on the high starch diet compared with the high sucrose diet, was observed. The anaerobe genera identified included Actinomyces, Bacteroides, Bifidobacterium, Clostridium, Eubacterium, Lactobacillus and Propionibacterium. Bacteroides was the most prevalent genus in both dietary groups (51.2 and 29.5% in the faeces of rats fed the sucrose and starch diets, respectively). In contrast, clostridia were prevalent in the starch-fed group (23.8%) and less so in the sucrose diet (11.5%), as propionibacteria were prevalent in faeces of rats fed the starch diet (15.5%), and low in the sucrose diet (3.9%). The remaining genera were scarce in faeces from rats on either diet. Total short-chain fatty acids (SCFA) were significantly higher in the faeces of animals fed the starch diet compared with those fed the sucrose diet. The relative concentrations of acetic, propionic and butyric acids were not significantly different between the two dietary groups. In conclusion, high starch diet can markedly modify the composition of faecal flora and alter considerably the faecal concentration of SCFAs, compound which might have a health-promoting effect.

An assessment of three selective media for bifidobacteria in faeces

Three previously described media enumerating Bifidobacterium spp. in faeces were compared with respect to their selectivity and quantitative recovery. The results of this study indicate that of the three media studied, Beerens' agar is the most suitable medium for isolation and enumeration of Bifidobacterium spp. from the gut microflora.